8377365: [BACKOUT] Mixed jstack cannot find function in vDSO

Reviewed-by: thartmann

Author: chhagedorn

src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2026, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -95,9 +95,6 @@ struct core_data {
    // part of the class sharing workaround
    int                classes_jsa_fd; // file descriptor of class share archive
    uintptr_t          dynamic_addr;  // address of dynamic section of a.out
-   uintptr_t          vdso_addr;     // address of vDSO
-   off64_t            vdso_offset;   // offset of vDSO in core
-   size_t             vdso_size;     // size of vDSO
    uintptr_t          ld_base_addr;  // base address of ld.so
    size_t             num_maps;  // number of maps.
    map_info*          maps;      // maps in a linked list

src/jdk.hotspot.agent/linux/native/libsaproc/ps_core.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2026, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -31,9 +31,6 @@
 #include <elf.h>
 #include <link.h>
 #include <errno.h>
-#include <sys/mman.h>
-#include <sys/sendfile.h>
-#include <sys/utsname.h>
 #include "libproc_impl.h"
 #include "ps_core_common.h"
 #include "proc_service.h"
@@ -288,8 +285,6 @@ static bool core_handle_note(struct ps_prochandle* ph, ELF_PHDR* note_phdr) {
             // We will adjust it in read_exec_segments().
             ph->core->dynamic_addr = auxv->a_un.a_val;
             break;
-          } else if (auxv->a_type == AT_SYSINFO_EHDR) {
-            ph->core->vdso_addr = auxv->a_un.a_val;
           }
           auxv++;
         }
@@ -355,10 +350,6 @@ static bool read_core_segments(struct ps_prochandle* ph, ELF_EHDR* core_ehdr) {
                   print_error("failed to add map info\n");
                   goto err;
                }
-               if (core_php->p_vaddr == ph->core->vdso_addr) {
-                  ph->core->vdso_offset = core_php->p_offset;
-                  ph->core->vdso_size = core_php->p_memsz;
-               }
             }
             break;
          }
@@ -602,39 +593,6 @@ static uintptr_t calc_prelinked_load_address(struct ps_prochandle* ph, int lib_f
   return load_addr;
 }
 
-// Check for vDSO binary in kernel directory (/lib/modules/<version>/vdso),
-// rewrite the given lib_name string if found.
-// Otherwise copy vDSO memory in coredump to temporal memory generated by
-// memfd_create().
-// Returns FD for vDSO (should be closed by caller), or -1 on error.
-static int handle_vdso(struct ps_prochandle* ph, char* lib_name, size_t lib_name_len) {
-  int lib_fd;
-  struct utsname uts;
-  uname(&uts);
-
-  // Check vDSO binary first (for referring debuginfo if possible).
-  char *vdso_path = (char*)malloc(lib_name_len);
-  snprintf(vdso_path, lib_name_len, "/lib/modules/%s/vdso/vdso64.so", uts.release);
-  lib_fd = pathmap_open(vdso_path);
-  if (lib_fd != -1) {
-    print_debug("replace vDSO: %s -> %s\n", lib_name, vdso_path);
-    strncpy(lib_name, vdso_path, lib_name_len);
-  } else {
-    // Copy vDSO memory segment from core to temporal memory
-    // if vDSO binary is not available.
-    lib_fd = memfd_create("[vdso] in core", 0);
-    off64_t ofs = ph->core->vdso_offset;
-    if (sendfile64(lib_fd, ph->core->core_fd, &ofs, ph->core->vdso_size) == -1) {
-      print_debug("can't copy vDSO (%d)\n", errno);
-      close(lib_fd);
-      lib_fd = -1;
-    }
-  }
-
-  free(vdso_path);
-  return lib_fd;
-}
-
 // read shared library info from runtime linker's data structures.
 // This work is done by librtlb_db in Solaris
 static bool read_shared_lib_info(struct ps_prochandle* ph) {
@@ -729,14 +687,9 @@ static bool read_shared_lib_info(struct ps_prochandle* ph) {
          // it will fail later.
       }
 
-      if (lib_name[0] != '\0') { // ignore empty lib names
-         // We can use lib_base_diff to compare with vdso_addr
-         // because base address of vDSO should be 0.
-         if (lib_base_diff == ph->core->vdso_addr) {
-           lib_fd = handle_vdso(ph, lib_name, sizeof(lib_name));
-         } else {
-           lib_fd = pathmap_open(lib_name);
-         }
+      if (lib_name[0] != '\0') {
+         // ignore empty lib names
+         lib_fd = pathmap_open(lib_name);
 
          if (lib_fd < 0) {
             print_debug("can't open shared object %s\n", lib_name);

test/hotspot/jtreg/serviceability/sa/LingeredAppWithVDSOCall.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2026, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -122,12 +122,6 @@ public void setForceCrash(boolean forceCrash) {
         this.forceCrash = forceCrash;
     }
 
-    private static Runnable crasher;
-
-    public static void setCrasher(Runnable runnable) {
-        crasher = runnable;
-    }
-
     native private static int crash();
 
     /**
@@ -634,12 +628,8 @@ public static void main(String args[]) {
             synchronized(steadyStateObj) {
                 startSteadyStateThread(steadyStateObj);
                 if (forceCrash) {
-                    if (crasher == null) {
-                        System.loadLibrary("LingeredApp"); // location of native crash() method
-                        crash();
-                    } else {
-                        crasher.run();
-                    }
+                    System.loadLibrary("LingeredApp"); // location of native crash() method
+                    crash();
                 }
                 while (Files.exists(path)) {
                     // Touch the lock to indicate our readiness